Selector switch



1l, Q E, NYGREN 2,503,885

SELECTOR SWITCH Filed April 10, 1948 3 Sheets-Sheet l 8% www A TWO/emi@C. E. NYGREN SELECTOR SWITCH April 11, 195o 3 Sheets-Sheet 2 Filed April1o, 1948 INVENTOR. CD1/,91152555 /I/V/EE/V April l1, 1950 c. E. NYGREN2,503,885

SELECTOR SWITCH Filed April 10, 1948 3 Sheets-Sheet 3 IOZv INVENTOR.CHARLES E. NYGRE/y ABY A Tron/Vey Patented Apr. 11, 1950 SELECTOR SWITCHCharles E. Nygren, Milwaukee, Wis., assignor to Globe-Union Inc.,Milwaukee, Wis., a corporation of Delaware Application April 10, 1948,Serial N0. 20,317

(Cl. ZOO-11) 3 Claims.

This invention relates to improvements in selector switches formultiple-circuit control, and particularly to indexing and positionreturn mechanisms for such switches.

The present application is a continuation in part `of the application ofCharles E. Nygren for improvements in a Selector switch, iiled August29, 1947, Ser. No. 771,297, and abandoned April 24, 1948.

Switches of this type are shown and described in Patentsv Nos. 2,291,516and 2,291,517, for "Selector switch, issued July 28, 1942, to Globe-Union Inc., the assignee of this application. The switches of thesepatents used a spring-biased detent engageable with indexing lugs forthe in dexing mechanism `and a separate position return spring. Whilesuch switches operate satis iactorily, the detent and lugs rapidly wearwhich unduly shortens the useful life of the switch. Also, theincorporation of a spring for the detent, as well as a return spring,unnecessarily multiplies the number of parts and increases manufacturingcost of the switch.

It is therefore an object of this invention to provide a selector switchhaving an indexing mechanism which will withstand wear better than thosenow in use and which will also function as a position return.

Another object of the invention is to provide a. selector switch inwhich the interchange of a single part adapts the switch for indexing inevery position or for indexing in some positions and spring returnableto an indexed position from other positions upon removal of manualforce.

And a further object of the invention is to provide a simple, compactselector switch which may be mounted singly or in groups for effectiveand reliable operation of a large number of circuits over longer periodsof time than was possible heretofore by switches of the present type.

These objects are obtained by providing a cam which rotates with therotor of the switch and a cam follower roller carried by a spring-biasedlever pivoted on the supporting plate of the switch. The cam may beformed in varying shapes as shown for the purpose of either indexing therotor in each of a plurality of selected y positions or indexing it insome of the selected. positions and returning it from other of selectedpositions to an indexed position. The cam may be either internal orexternal in design. If the rotor is mounted for limited reciprocalrotation within angular limits of say 60 (such as is the case when therotor is operated by a lever which projects radially through a slot inthe base.) an internal cam is most adaptable. If the rotor hasreciprocal rotation through angular movements of say 150 or more (suchas is the case when the rotor is operated by a laterally projectingshaft) an external type of cam is most adaptable.

In either event, a single spring functions to perform the indexing aswell as the position return action of the rotor. The cam follower rollerand its lever may be incorporated within the narrow contines of theswitch-supporting bracket and still provide suilicient bearing surfaceof a low frictional nature to withstand wear and thus lengthen theuseful life of the switch.

The novel features, which areconsidered characteristic of the invention,are set forth with particularity in the appended claims. vention itself,however, both as to its organization and its method of operation,together with additional objects and advantages thereof, will best beunderstood from the following description of a specific embodiment whenread in connection with the accompanying drawings, in which:

Fig. 1 is a top plan view of a switch embodying the present inventionwith some of the contacts omitted for sake of clarity in illustration;

Fig. 2 is a view in front elevation of the switch viewed in Fig. 1;

Fig. 3 is a sectional view taken on the line III- IU of Fig. 2;

Fig. 4 is a fragmentary front elevational view of the switch viewed inFig. 1 with portions broken away for sake of clarity in illustration;

Fig. 5 is a top plan view of the hanger bracket, bell crank lever andcam follower roller comprising elements of the indexing and returnposition mechanism;

Fig. 6 is a view in front elevation of the mechanism viewed in Fig. 5;

Fig. 'T is a View in elevation of the bell crank lever shown in Figs. 5and 6;

Fig. 8 is a view in elevation of the rotor lever incorporating one typeof internal cam;

Figs. 9 and 10 are views in front elevation of rotor leversincorporating modified forms of internal cams;

Fig. 11 is a top plan View of another modication of a switch embodyingthe present inven tion;

Fig. 12 is a sectional view taken on the line XII- XII of Fig. 1l; and

Fig. 13 is a view in front elevation of a modified form of external cam.

Referring to the drawings by reference numerals, many of the elements ofthe modifications of the switch herein described are shown and describedin detail in the aforementioned patents and reference is herein made tosuch patents for such detailed description. In general all modicationsof the switch include a stator 2l of insulating material, which carriesiixed contacts 28 and 2S varying in number and location depending uponthe nature of the circuit to be controlled, and a rotor 33 of insulatingmaterial rotatably mounted within the contines of the stator andcarrying contact members 34 and 35 which slidably selectively engagewith the xed contacts 28 and 29 upon rotation of the rotor.

In the modifications shown in Figs. 1 to 4, inclusive, the stator 21 issubstantially half an ellipse because the rotor 33 is confined toangular movement within limits of approximately 60. In the modificationof Figs. 11 and 12 the stator 21 is substantially a full ellipse as therotor may have angular movement of 150 or more. Stators of the fullellipse type are shown and fully described in Patent No. 2,186,949,issued January 16, 1940, to K. C. Allison, et al., for Electric switch.

Referring now to the modification viewed in Figs. 1 to 10, inclusive,the stator and rotor are carried in a mounting l5 having a base i6 andan integral side plate I1. A supporting plate I3 staked to the base I6completes the mounting. The side plate l1 has end ears 22 to which thestator 21 is secured and a central ear 23 which serves as one supportfor the rotor pivot 32. The other end of pivot 32 is supported in thesupporting plate i8. An operating lever, including a body portion 35, atang 31, and two wing portions 38, is rotatably mounted on the pivot 32with the tang 31 extending through a slot in the base I5. Both the lever35 and the rotor 33 are fixed on a common hub which rotates on the pivot32. Thus the swinging of the lever by a handle 38 controls reciprocalrotation of the rotor 33.

The indexing of the rotor 33 in selected positions, and the return ofthe rotor from other positions to an indexed position, are controlled bya cam and a spring-biased cam rider. Various shapes of internal cams areshown in Figs. 8, 9 or 10. The cam shape shown in Figs. 2, 3, and 8 hascurved surfaces 43 and 44 defining the end limits of cam travel andsloping surfaces 45 and 46 rising from a low point which defines' acentral indexed position. A cam follower roller 52 rolls on the surfaces45, 46. It is mounted on one end of a bell crank lever 58 pivoted at '5|on the supporting plate I8. A lateral ear 53 on the other end of thebell crank 5l) extends over the edge of the supporting plate I8 and isattached to one end of a helical spring 51, the other end of such springbeing secured to an ear 58 on the supporting plate I8. Thus the switchmounting, spring, and bell crank lever are closely organized andcompactly arranged within the limited space available. Withthisconstruction the switch may be manually moved to either of two endpositions and manually held there, but as soon as the manual pressure isreleased the rotor will move to the central position under the action ofthe cam follower roller 52 pressing against the sloping surfaces 45 or46. Movement of the rotor to either end position may be limited byengagement of the tang 31 with the ends of the slot or by the roller 52engaging with the surfaces 43 or 44.

If it is desired to provide a switch in which the rotor is indexed andheld in one end position and is returnable to center indexed positionfrom the other end position upon removal of the manual' pressure, theinternal cam is shaped as shown in Fig. 9. In such cam the curvedsurface 54 and the sloping surface 65 correspond to the curved surface44 and sloping surface 46, respectively of the cam of Fig. 8. The lowpoint between rise 61 and surface 65 defines the center indexingposition, while the low point between sloping surface 63 and rise 61defines may define a limit to such end position while rise 65 completesthe internal cam. With the cam of Fig. 9 the cam roller 52 will rollover the rise 61 and index the rotor in either the center or left endposition. However, to hold the rotor in the right end position, manualforce is necessary to keep the roller 52 from riding down the camsurface 65 and forcing the rotor to center position. Thus the rotor hasone position in which it may be positively indexed, a second positioninto which the rotor may be moved and manually held, and a centralposition to which the rotor automatically returns from such manuallyheld position.

In the modification shown in Fig. 10, the cam has three low surfaces 1|,12, and 15 which define three indexing positions. These low surfaces areseparated by rises 15 and 11. 'Hence the rotor may be indexed and heldin either one of three indexing positions. Manual pressure, however, isnecessary to overcome the force of the spring and move the rotor out ofone position to a point at which the roller 52 rides over either therise 16 or 11 and to cause the rotor to move into an adjacent indexingposition.

Referring now to the modification viewed in Figs. 1l to 13, inclusive,the stator and rotor unit are mounted on a supporting plate by means oflaterally projecting bolts 8| carried by such plate. The stator 21 isspaced from the plate 80 by tubular spacers 82 on the Shanks of thebolts 8l. It is thus possible to mount a plurality 'of stator and rotorunits in spaced relationship on the bolts 8|. However, for the purposeof this invention 'only one stator and rotor unit is shown. Av shaft 83is rotatably carried in a bearing 84 fixed to the plate 80.` Opposed ats85 are milled on the shaft 83 to non-rotatably hold the rotor and thecam body. It is .also desirable to mill a single flat 86 on the outerend "of the shaft 83 so that it may non-rotatably rec eive and hold anoperating knob (not shown). In this modification, if there were no otherrestriction the rotor would have angular movement through 360. However,for practical purposes the angular movement of the rotor is limited ashereinafter described.

The indexing of the rotor in selected positions, and the return thereoffrom other non-indexing positions to indexed positions, areaccomplished, as in the previous modification, by a cam andspring-biased cam follower roller, the construction of which is similarto that previously described. However, in this modification the cam body81 is staked to the shaft 83 between the plate 80 and the rotor statorunit and there is no projection tang. The cam body because of greaterangular movement has an external cam rather" than an internal cam. As inthe previously described modification there is a cam follower roller 88which rides on the external cam surfaces. However, this roller ismounted intermediate the ends of a lever 89, the inner end of which ispivoted at 9U to the plate 88. 'Ihe lever is spring-biased to urge theroller toward the cam by a spring 9i connected to the free end of thelever 89 and to an ear 92 projecting from the plate 89. Operative spacefor the spring 9| may be provided by cutting back a portion of the plate89, as indicated at 93. As is shown in Fig. 11, the lever 89 is offsetso that its free end lies substantially in the plane of the plate 80while the central portion is spaced from such plate to provide forfreedom of movement. 1

The form of the external cam shown in Fig. 12 has three low points 94,95, and 96, which define three positions in which the rotor will bepositively indexed. In addition, this cam has two sloping surfaces 91and 98 which when acted upon by the cam follower 88 cause the came andthe rotor to rotate from either of the two end extremes of travel toeither the index positions 94 or 96 whenever manual holding force isremoved from the shaft 8B. The two extremes of travel or end positionsare determined by the abutment between a lug 99 formed from the plate B0and either of the edge portions or |0| formed on the cam body 8l. Aselector switch with such a cam can be manually moved to and manuallyheld in either of the two extreme positions. Upon release of the manualforce the rotor will snap back to an adjacent indexed position. As isthe case with the cam of Fig. 10-, the rotor may be manually moved outof one indexed position to a point at which it will snap into anadjacent indexed position.

The cam shown in Fig. 13 has only one low point |02 and two slopingsurfaces |03 and |04. This cam operates substantially identical with thecam of Fig. 8. When this cam is substituted for the cam of Fig. l2, theswitch will always be movable to the central indexed position. It may bemanually moved and forcibly held in either of two extreme positions,such extremes being determined by the relative angular positioning ofabutting edges |00 and |0|. A selector switch provided with this camoperates in substantially the same manner as the selector switchprovided with the cam of Fig. 8.

A common feature of all of the modifications is that a single springassociated with a single cam follower roller performs in conjunctionwith a cam of desired design both the function of indexing the switchrotor and spring-biasing the switch rotor so that it will automaticallyreturn from a non-indexed position to an indexed position upon therelease of the manual force moving the rotor to non-indexed position. Inall modifications the spring and lever for the cam follower roller areso structurally related to the mounting bracket or plate that a, minimumamount of space is required therefor. With the type of constructiondescribed, it is also possible to use hardened parts for the Wearingsurfaces of both the cam and the cam follower roller and the frictiontherebetween may be kept to a minimum and the effective life of theswitch increased.

Although only several embodiments of the invention are shown anddescribed herein, it will be understood that this application isintended to cover such other changes or modifications as come within thespirit of the invention or scope of the following claims.

I claim:

1. A movable contact switch comprising a bracket with a mounting baseportion and a support portion, a switch stator mounted on said supportportion, a plurality of fixed contacts mounted on said stator ininsulated relation, a supporting plate fixed on said base portion andextending substantially parallel to said support portion, a common hubrotatably mounted between said support portion and said supportingplate, a switch rotor fixed on said hub, a plurality of contacts mountedon the rotor in insulated relation,

a lever fixed on said hub and extending through 7 said base portion,said lever having an aperture with a plurality of cam surfaces, a bellcrank lever pivoted on said supporting plate, a cam follower roller onone end of said bell crank lever engageable with said cam surfaces, anda, spring urging said bell crank lever to cause said roller to be inengagement with the cam surfaces, said cam surfaces and said rolleracting to index said switch rotor and cause its movement over a desiredrange.

2. A selector switch comprising a mounting member, a stator ofinsulating material having fixed contacts and carried on said member, arotor of insulating material associated with said stator and havingcontacts which selectively engage said fixed contacts, said rotor beingrotatable with respect to said stator to a first extreme position, acentral position and a second extreme position to establish differentcontacts, a bearing fixed t0 said member, a shaft member rotatablycarried in said bearing and having a driving connection with said rotor,said shaft member being manually movable to bring said rotor intoselected ones of said positions, and indexing mechanism for indexing andholding said rotor in said central position and said first extremeposition and acting to return said rotor to said central position fromsaid second extreme position upon removal of manual pressure holdingsaid shaft member and rotor in said second extreme position, saidmechanism including, a cam mounted on one of said members and having arise between a low point delining said central position and a lovv pointdefining said first extreme position, Said cam also having a surfacedefining said second extreme position, a cam follower mounted on theother of said members, and spring means cooperable with said follower toreturn said rotor to said central position from said second extremeposition upon removal of manual pressure holding said shaft and rotor insuch second extreme position.

3. In a selector switch having a contact carrying stator and rotorrelatively movable to a plurality of positions for establishingdifferent contacts, means for indexing said stator and rotor in a firstposition and moving said stator and rotor out of a second position inwhich said stator and rotor are manually held, comprising a cam and camfollower relatively movable in synchronism with the relative movement ofsaid stator and rotor, said cam having a low point in which saidfollower rests to index said stator and rotor in said first position,said cam having a sloping surface up which said cam follower rides assaid stator and rotor are moved to said second position, abutment meansto limit the relative movement of said cam and rotor when said statorand rotor reach said second position, and spring means for urging saidcam follower into engagement with said cam with sufficient force tocause said cam follower to ride down said sloping surface upon removalof manual pressure holding said stator and rotor in said second positionwhereby a single spring operating through said cam and cam follower`functions to index said switch and move said switch out of a manuallyheld position.

CHARLES E. NYGREN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,291,516 Wolff July 28, 19422,411,013 Warnke Nov. 12, 1946 2,418,564 Wallace Apr. 8, 194'7 2,444,471Samiran et al July 6, 1948

